1. General Field
The current disclosure relates generally to apparatus, systems and methods for tracking objects. More particularly, the apparatus, systems and methods relate to tracking object using audio sensors distributed around an airfield. Specifically, the apparatus, systems and methods provide for applying beamforming algorithms on audio signals emitted by objects to track the objects.
2. Description of Related Art
One of the most critical tasks at any airport is tracking all aircraft at or near the airport. Traditionally, this is accomplished through one or a combination of ground tracking radars and visual means. However, ground tracking radars are complex and extremely expensive making them impractical for smaller commercial airports and many forward deployed military air stations. Furthermore, aircraft that are on the ground or otherwise at very low altitude are typically below radar tracking capabilities or in radar “shadow zones” such as behind the edge of a hangar or building.
Unfortunately, human visual observation and electro-optical sensors often suffer from limitations similar to those of radar. Visual methods can be even more subject to physical obstruction than radar and also suffer from severe limitations in low-visibility conditions such as darkness, fog, rain, or snow. Therefor a need exists for an aircraft tracking system that is effective at low altitudes for all environmental conditions.
Previous attempts to track objects (i.e., airplanes) around an airfield utilizing acoustical sensors are known to exist. Two such examples are provided in United States Patent Application Publication 2010/0284249 (the '249 publication) and in United States Patent Application Publication 2009/0257314 (the '314 publication). In each of the '249 publication and the '314 publication, a plurality of nodes are positioned throughout an airfield and are able to observe and “listen” for acoustical signatures of nearby aircraft. Further, in each of the '249 publication and the '314 publication, only a single node (i.e., sensor) is positioned at a single location.